Warehouse Keeper Mia:

We need at least 10 pieces of the key and 1 Records Chest in order to find open it and find the evidence our client has asked for.
Go to the *Field of Silence* and get rid of the *Tasaba Lizardmen and Tasaba Lizardman Shaman* there. Once you have done so, you will be able to obtain *both the pieces of the key to the Records Chest and the Records Chest itself*.